This invention relates to movable spindle tool machines and, more particularly, to improvements in a movable spindle tool machine to satisfy increased throughput requirements.
A movable spindle tool machine in one form comprises a drilling machine. Drilling machines have been used, for example, for printed circuit board applications, such as in laminated chip carriers (LCC). Many of these machines include many spindles. The spindles are positioned during set-up to various locations. The most common type of drilling machine is a beam mounted machine that provides a single spindle for each work station. Each station acts on a workpiece at one time. Thus, if there are six stations, then there are six spindles. Another type of drilling machine used in high production operations is a matrix drilling machine. The spindles are provided in an array. The location of the spindles are not changed. The movable spindle LCC line driller is a cross between the traditional beam-mounted spindle drilling machine and air spindle matrix drillers. The line driller has the advantage of being able to automatically move the spindles to a fixed spacing that maximizes the hit rate based on the pitch of the LCC pattern on the panel.
In movable spindle tool machines of the type discussed the multiple spindles must be positioned prior to running the desired application. It is desirable to provide a means to automatically position the spindles. The conventional method is to provide a separate positioning system for each spindle. This can be expensive and requires a separate positioning system for each spindle which takes up a substantial amount of space. This minimizes the number of tools that can be used in a given area thereby limiting enhancements in machine productivity.
It is often necessary to replace a tool used in the spindle. This can be done manually. Advantageously, the process is automated. The spindle typically has a collect for holding the tool. The position of the tool must be located properly so that it can be inserted and maintained in the collect during a tool change operation. Also, the typical tool changers are adapted to change each tool independently. This can increase set-up time. Further, a drive system should operate independent of pitch.
In drilling machine applications it is important to determine if a drill bit is broken. Known methods range from microwave guide distortion, to acoustic vibration, to optical chip detectors. The most widespread method uses an optical through-beam pair of sensors to detect the presence or absence of the drill. However, to complicate the matters, drill bits sometimes only break off the tip of the drill. This has a tendency to fool most detectors because a through-beam pair typically looks higher up the drill flutes. Through-beam pairs are also limited by the minimum separation in the accuracy of alignment between the sender and receiver tips which impacts reliable detection of smaller drill diameters.
The present invention is directed to overcoming one or more of the problems discussed above, in a novel and simple manner.
In accordance with the invention, a movable spindle tool machine is adapted to increase production productivity.
In one aspect of the invention, a movable spindle tool machine includes a pre-spindle tool locator.
In another aspect of the invention, a movable spindle tool machine includes a positioning system for two or more movable assemblies.
In still another aspect of the invention, a movable spindle tool machine includes nesting movable tool carriages.
In accordance with still another aspect of the invention, a movable spindle tool machine includes a location independent tool or button changer for linear spindle arrays.
In accordance with a further aspect of the invention, a movable spindle tool machine includes a light pipe bit detector incorporated in a removable pressure foot button.
In one embodiment of the invention there is disclosed a movable spindle tool machine including a base and a spindle mounted to the base. A magazine is mounted proximate the spindle for storing a supply of tools. A tool changer is movably mounted relative to the base for transferring tools from the magazine for insertion into the spindle. A tool locator is mounted in line with the spindle. The tool changer is operable to initially transfer a tool from the magazine to the tool locator to align the tool with the spindle and thereafter transfer the tool to the spindle for insertion into the spindle.
There is disclosed in accordance with another embodiment of the invention a movable spindle tool machine including a base and a plurality of spindles. A plurality of bars, one for each spindle, and each supporting one of the spindles, are movably mounted to the base to position the spindles relative to one another. A drive assembly is mounted to the base for driving a linear actuator. Clamping means are operatively associated with each bar for selectively engaging the individual bars with the linear actuator to thereby selectively enable movement of the individual spindles relative to one another.
There is disclosed in accordance with a further embodiment of the invention a movable spindle tool machine including a base and a spindle mounted to the base. A magazine is mounted proximate the spindle for storing a supply of tools. A tool changer is movably mounted relative to the base for transferring tools from the magazine for insertion into the spindle wherein the tool changer comprises a relatively rigid fixed jaw and a relatively flexible movable jaw. An actuator selectively moves the movable jaw toward the fixed jaw to grip a tool therebetween.
There is disclosed in accordance with an additional embodiment of the invention a movable spindle tool machine including a base and a plurality of spindles. A plurality of carriages, one for each spindle and each supporting one of the spindles, are movably mounted to the base to position the spindles relative to one another. Each carriage comprises a narrow bar mounted to the spindle to provide minimal spacing between the spindles and an outrigger framework attached to the narrow bar to effectively increase the width of the bar. A linear drive stage is mounted to the base and the carriages for selectively positioning the spindles.
There is disclosed in accordance with yet another embodiment of the invention a spindle tool machine including a base and a spindle mounted to the base having a drill bit for drilling a workpiece. A pressure foot is operatively associated with the spindle to apply pressure to the workpiece during a drilling operation. The pressure foot includes a downwardly opening recess. A button is mountable in the pressure foot recess. The button comprises a two-piece button having first and second halves mateable to define a center opening for a drill bit. First and second light pipes are disposed between the two halves in alignment with each other and concentric with a center of the center opening. The light pipes are operatively associated with optical fibers for detecting a drill bit at the center opening.